The correlation of TNF alpha levels with acute phase proteins in acute Toxoplasma gondii infection in mice

Preparation of Dendrobium officinale Polysaccharide by Lactic Acid Bacterium Fermentation and Its Protective Mechanism against Alcoholic Liver Damage in Mice

Dendrobium officinale polysaccharide (DP) was prepared with lactic acid bacterium fermentation to overcome the large molecular weight and complex structure of traditional DP for improving its functional activity and application range in this work. The structure was analyzed, and then the functional activity was evaluated using a mouse model of alcoholic liver damage. The monosaccharide compositions were composed of four monosaccharides: arabinose (0.13%), galactose (0.50%), glucose (24.38%), and mannose (74.98%) with a molecular weight of 2.13 kDa. The connection types of glycosidic bonds in fermented D. officinale (KFDP) were →4)-β-D-Manp(1→, →4)-β-Glcp(1→, β-D-Manp(1→, and β-D-Glcp(1→. KFDP exhibited an excellent protective effect on alcoholic-induced liver damage at a dose of 80 mg/kg compared with polysaccharide separated and purified from D. officinale without fermentation (KDP), which increased the activity of GSH, GSH-Px, and GR and decreased the content of MDA, AST, T-AOC, and ALT, as well as regulated the level of IL-6, TNF-α, and IL-1β to maintain the normal functional structure of hepatocytes and retard the apoptosis rate of hepatocytes. The results proved that fermentation degradation is beneficial to improving the biological activity of polysaccharides. The potential mechanism of KFDP in protecting alcoholic liver damage was inhibiting the expression of miRNA-150-5p and targeting to promote the expression of Pik3r1. This study provides an important basis for the development of functional foods.

Bacillus cereus CwpFM induces colonic tissue damage and inflammatory responses through oxidative stress and the NLRP3/NF-κB pathway

Bacillus cereus (B. cereus) from cow milk poses a threat to public health, causing food poisoning and gastrointestinal disorders in humans. We identified CwpFM, an enterotoxin from B. cereus, caused oxidative stress and inflammatory responses in mouse colon and colonic epithelial cells. Colon proteomics revealed that CwpFM elevated proteins associated with inflammation and oxidative stress. Notably, CwpFM induced activation of the NLRP3/NF-κB signaling, but suppressed antioxidant NFE2L2/HO-1 expression in the intestine and epithelial cells. Consistently, CwpFM exposure led to cytotoxicity and ROS accumulation in Caco-2 cells in a dose-dependent manner. Further, NAC (ROS inhibitor) treatment abolished NLRP3/NF-κB activation due to CwpFM. Moreover, overexpression of Nfe2l2 or activation of NFE2L2 by NK-252 reduced ROS production and inhibited activation of the NLRP3/NF-κB pathway. Inhibition of NF-κB by ADPC and/or suppression of NLRP3 by MCC950 attenuated CwpFM-induced inflammatory responses in Caco-2 cells. Collectively, CwpFM induced oxidative stress and NLRP3/NF-κB activation by inhibiting the NFE2L2/HO-1 signaling and ROS accumulation, leading to the development of intestinal inflammation. Our data elucidate the role of oxidative stress and innate immunity in CwpFM enterotoxicity and contribute to developing diagnostic and therapeutic products for B. cereus-related food safety issues.

Hydroxy Selenomethionine Exert Different Protective Effects Against Dietary Oxidative Stress-Induced Inflammatory Responses in Spleen and Thymus of Pigs

Oxidative stress (OS) is widespread in animal husbandry, which causes edema in immune organs and suppresses immune function of animals. Selenium (Se) is an essential trace element involved in immune regulation and improves animals' immunity. In present study, growing and finishing pigs were used to determine the protective effects of the new organic Se (hydroxy selenomethionine, OH-SeMet) on dietary oxidative stress (DOS) induced inflammatory responses, and the corresponding response of selenotranscriptome in spleen and thymus. Forty castrated male pigs (25.0 ± 3.0 kg) were randomly grouped into 5 dietary treatments (n = 8) and fed on basal diet (formulated with normal corn and normal oils) or oxidized diet (formulated with aged corn and oxidized oils) supplied with 0.0, 0.3, 0.6, or 0.9 mg Se/kg OH-SeMet, after 16 weeks, the corresponding indicators were determined. Results showed that DOS moderately increased the spleen and thymus index, decreased the antioxidant capacity of serum, spleen and thymus, and increased the concentration of serum inflammatory cytokines (IL-6 and TNF-α). The inflammatory response in spleen and thymus under DOS were discrepancies, DOS increased the expression of inflammation-related gene (IFN-β and TNF-α) in thymus, while exhibited no impact on that of the spleen. Dietary OH-SeMet supplementation exhibited protective effects, which decreased the spleen and thymus index, improved the antioxidant capacity of serum, spleen and thymus, and decreased the serum IL-1β and IL-6 levels. Se supplementation exhibited limited impact on the inflammation-related genes in spleen, except decreased the mRNA expression of IL-8. On the contrary, Se supplementation showed more impact on that of the thymus, which decreased the mRNA expression of IL-8 and TNF-α, increased the expression of IFN-β, IL-6, IL-10, and MCP1. In addition, selenotranscriptome responsive to dietary Se levels in spleen and thymus were discrepancies. Se supplementation increased the mRNA expression of  the selenotranscriptome in thymus, while exhibited limited impact on that of in spleen. In conclusion, dietary OH-SeMet supplementation mitigates the DOS-induced immunological stress by increasing the antioxidant capacity and altering the expression of inflammation-related genes and selenotranscriptome in immune organs, and these response in spleen and thymus were discrepancies.

Toxoplasma gondii eIF-5A Modulates the Immune Response of Murine Macrophages In Vitro

Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan that can elicit a robust immune response during infection. Macrophage cells have been shown to play an important role in the immune response against T. gondii. In our previous study, the eukaryotic translation initiation factor 5A (eIF-5A) gene of T. gondii was found to influence the invasion and replication of tachyzoites. In this study, the recombinant protein of T. gondii eIF-5A (rTgeIF-5A) was incubated with murine macrophages, and the regulatory effect of TgeIF-5A on macrophages was characterized. Immunofluorescence assay showed that TgeIF-5A was able to bind to macrophages and partially be internalized. The Toll-like receptor 4 (TLR4) level and chemotaxis of macrophages stimulated with TgeIF-5A were reduced. However, the phagocytosis and apoptosis of macrophages were amplified by TgeIF-5A. Meanwhile, the cell viability experiment indicated that TgeIF-5A can promote the viability of macrophages, and in the secretion assays, TgeIF-5A can induce the secretion of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and nitric oxide (NO) from macrophages. These findings demonstrate that eIF-5A of T. gondii can modulate the immune response of murine macrophages in vitro, which may provide a reference for further research on developing T. gondii vaccines.